www-with-node-js-and-express

srini.js

var express = require("express");
var app = express.createServer();
var port = 9090;

app.all(/.*/, function(req, res, next) {
  var host = req.header("host");
  if (host.match(/^www\..*/i)) {
    next();
  } else {
    res.redirect(301, "http://www." + host);
  }
});

app.use(express.static(__dirname + "/public"));
app.listen(port);